Rome ? Italy’s parliament headed toward an unprecedented split today between Premier Silvio Berlusconi’s conservative coalition and one led by his center-left rival – the result of a national vote that could stall the formation of a new government.

Final results in the two-day vote ending Monday showed Romano Prodi’s center-left coalition winning control in the lower house of parliament, with 49.8 percent of the vote compared to 49.7 won by Berlusconi’s conservatives.

According to the results, Berlusconi’s center-right coalition held a one-seat lead in the Senate, al-though six seats elected abroad were still to be counted.

“We have won, and now we have to start working to implement our program and unify the country,” said a jubilant Prodi, speaking to his supporters. “Until the very end we were left in suspense, but in the end victory has arrived.”

Berlusconi’s spokesman contested the victory claim, and Prodi’s allies later conceded that results in the Senate were still not complete.

During his tenure as premier, Berlusconi, a flamboyant billionaire, had strongly supported President Bush over Iraq despite fierce Italian opposition to the war. Prodi, an economist, said he would bring troops home as soon as possible, security conditions permitting. But the issue was largely deflated before the campaign began, when Berlusconi announced that Italy’s troops there would be withdrawn by year’s end.

The Senate and lower chamber of parliament have equal powers, and any coalition would have to control both in order to form a government. Both center-left and center-right leaders have said if neither side controls both houses, new elections should be called.

If parliament is split, President Carlo Azeglio Ciampi – a grandfatherly, highly respected economist and independent from partisan politics – could try to name a government of technocrats at least until another election. He could also seek to fashion a coalition of left and right, but considering the bitter divisions among Italy’s political parties, that seemed unlikely.

There is no clear provision in the Italian constitution to deal with a split parliament, and there are no precedents.

Berlusconi, a 69-year-old media mogul and Italy’s longest-serving premier since World War II, was battling to capture his third term with an often squabbling coalition of his Forza Italia party, the former neo-fascist National Alliance, pro-Vatican forces and the anti-immigrant Northern League.

The 66-year-old Prodi, a former premier, was making his comeback bid with a potentially unwieldy coalition of moderate Christian Democrats, Greens, liberals, former Communists and Communists.

Italians were mainly preoccupied by economic worries. Berlusconi failed to jumpstart a flat economy during his tenure, but promised to abolish a homeowner’s property tax. Prodi said he would revive an inheritance tax abolished by Berlusconi, but only for the richest; he also promised to cut payroll taxes to try to spur hiring.